In addition to the rapid spread of wireless LAN apparatuses as represented by IEEE802.11b, there is expected a society established with a seamless network by wirelessly connecting AV apparatuses and personal computers one with another. It is the urgent need to establish a technology for realizing small-sized, high-speed data communication apparatuses at low cost.
Among these, attentions are drawn to the communication scheme called UWB using pulse-formed modulation signals.
FIG. 1 shows an example of a block arrangement of a conventional UWB wireless apparatus described in PCT International Publication No. 01/93442. During transmission, transmission data in a control & interface 5101 is formed into a transmitting data string and inputted to a transmitting-function section 5102. The transmission data inputted to the transmission-function section 5102 is primarily modulated by an encoder 5103, pulse-modulated in a pulse modulator 5104, adjusted in transmission level, removed of unwanted frequency components, etc. in a transmission front end 5105, and then sent out at an antenna 5106.
During reception, the signal received at a reception antenna 5109 is received in the reception-function section 5108, adjusted to a suited level and removed of unwanted frequency in a reception front end 5110, and then inputted to a waveform correlator 5111. The correlation information generated at the waveform correlator 5111 is forwarded to a timing adjuster 5112 where it is determined in synchronism if exceeding a given correlation value. Meanwhile, in the case that the correlation information is not determined in synchronism, the synchronizing signal in the reception-function section 5108 is deviated in timing, again taking a correlation in the waveform correlator 5111. This is repeated until a synchronism is established. Thereafter, demodulation is carried out in a decoder 5113 to acquire reception data to be delivered to the control & interface 5101.
However, in the conventional arrangement UWB wireless apparatus arrangement and synchronization method therewith wherein synchronism is established by taking a waveform correlation based on a synchronous frame of the reception signal and thereafter data demodulation is carried out, it takes a long time required in synchronization thus lowering the transmission speed of actual information. Besides, there has been a problem the state occurs which the correlation pulse is at a high level due to an interference wave of a radio wave from a multipath or another apparatus. In order to resolve these problems, there is a proposal on the arrangement for removing of interference waves by determining, phase by phase, the level of a correlation pulse or providing the reception systems in plurality. However, this complicates the determination flow and increases the size of apparatus arrangement, thus increasing power consumption and raising apparatus price.